Subject: Question about draft-nordmark-multi6-noid-01.txt

From: Juan Rodriguez Hervella <[email-masked]>
Date: Tue, 28 Oct 2003 16:18:24 +0100

Hello multi6'ers:

I've just read NOID draft (may be I've read it too fast ) and
I haven't found anywhere how to re-write the source 
address.  If the packet doesn't have any extra
option/extension header to carry the additional prefix(es),
how can the router make this rewriting ?

Thanks!

-- 
JFRH

---

From: Erik Nordmark <[email-masked]>
Date: Tue, 28 Oct 2003 16:24:53 +0100 (CET)

> how can the router make this rewriting ?

The border router checks whether rewriting is allowed by looking at the nexthdr
field in the IPv6 header. If it is between P1 and P1+7 (a to be defined range
of "protocol values") then rewriting is ok.

The source address field is then modified to have high-order bits
(high-order 48 bits in many cases) which corresponds to the exit
the border router is using. For instance, if it is sending a packet
to an ISP who was delegated prefix 2000:1:2::/48 then
it will place that value in the top 48 bits of the source address.

Thus the router doesn't need to have a list of prefixes to choose between
as part of the packet.

  Erik